The SC regulates EGFR tyrosine kinase inhibitor resistance, PD-L1 expression, and the PD-1 checkpoint, as well as TNF, EGFR, VEGF, HIF-1, FoxO, relaxin, ErbB, and IL-17 signaling pathways, primarily in IPF. Here, HIF1A is linked to idiopathic pulmonary fibrosis.